CVE-2026-98243

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: dma-buf/dma-fence: fix checking signaling bit for timeline and driver name v3 The patch "dma-buf: dma-fence: Fix potential NULL pointer dereference" changed the check to test for the ops pointer instead of the signaled bit to avoid a potential NULL dereference when the ops pointer has been cleared. The problem is now that the ops pointer is cleared only when neither the release nor the wait callback is implemented and this isn't true for a lot of dma_fence implementations yet. So those implementations lost the RCU protection after signaling of the returned string resulting in potential use after free. Add the signaling check additional to the ops pointer check so that we have both the protection against NULL dereference as well as the RCU protection after signaling for the returned string. v2: improve comments to note RCU protection and explain why we check both signaling state and ops pointer v3: some comment improvements suggested by Philip

Severity

HIGH

CVSS score

7.1 (v3.1)

Vulnerability status

Received

Source identifier

416baaa9-dc9f-4396-8d5f-8c081fb06d67

Published

2026-10-06 09:18:12.383000

Last modified

2026-10-19 10:18:25.193000

View original CVE JSON

{
  "id": "CVE-2026-98243",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-10-06T09:18:12.383",
  "lastModified": "2026-10-19T10:18:25.193",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ndma-buf/dma-fence: fix checking signaling bit for timeline and driver name v3\n\nThe patch \"dma-buf: dma-fence: Fix potential NULL pointer dereference\"\nchanged the check to test for the ops pointer instead of the signaled\nbit to avoid a potential NULL dereference when the ops pointer has been\ncleared.\n\nThe problem is now that the ops pointer is cleared only when neither the\nrelease nor the wait callback is implemented and this isn't true for a lot\nof dma_fence implementations yet. So those implementations lost the RCU\nprotection after signaling of the returned string resulting in potential\nuse after free.\n\nAdd the signaling check additional to the ops pointer check so that we\nhave both the protection against NULL dereference as well as the RCU\nprotection after signaling for the returned string.\n\nv2: improve comments to note RCU protection and explain why we check\n    both signaling state and ops pointer\nv3: some comment improvements suggested by Philip"
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "drivers/dma-buf/dma-fence.c",
            "include/linux/dma-fence.h"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "035219a760edb35ae9a9e96beba7f122e26a997b",
              "lessThan": "a4db25b8949d6ff9c1a685a1273a015e8bab29db",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "035219a760edb35ae9a9e96beba7f122e26a997b",
              "lessThan": "3ed11c671ff7ec58c8fd96410233c677df23f407",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "15ecfdf0ef6f6d874d0a26690d300857b39ebfd0",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "7.1.5",
              "lessThan": "7.2",
              "versionType": "semver",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "drivers/dma-buf/dma-fence.c",
            "include/linux/dma-fence.h"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "7.2",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "7.2",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.2.8",
              "lessThanOrEqual": "7.2.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.3",
              "lessThanOrEqual": "*",
              "versionType": "original_commit_for_fix",
              "status": "unaffected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H",
          "baseScore": 7.1,
          "baseSeverity": "HIGH",
          "attackVector": "LOCAL",
          "attackComplexity": "LOW",
          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "NONE",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 5.2
      }
    ]
  },
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/3ed11c671ff7ec58c8fd96410233c677df23f407",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/a4db25b8949d6ff9c1a685a1273a015e8bab29db",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ]
}